Are morning after pills safe for use in place of regular birth control?

Patient: If the morning after pill is so safe to use, why are women advised not to use it regularly? Is it safe for repeated use in a short spam of time? Such as 8 in a span of 4 months? There has been debate in my circle of friends and it would be nice to have this clarified. Thanks!

Doctor: The dosage of hormones used for the purpose emergency contraception is relatively higher than that used in regular birth control pills. Thus morning after pill or emergency contraceptive pill is not intended for the use as a routine form of birth control. For example, the regular birth control may contain 0.10 mg of levonorgesterol and 0.02 mg of ethinyl estradiol, as opposed to a total of 1 mg  of levonorgesterol, every time you use the morning after pill. Hope this helps.